Selecting Newest Record

Question

Using Oracle eBusiness Suite.
Users can raise one requisition, and have it convert through to a PO. They can then raise a new requisition, and ask for it to be added to the existing, original PO.
That leaves a scenario where a PO can have 1+ requisitions linked to it.
I am trying to write some SQL to extract the requisition_header_id of the latest requisition that has been linked to a PO.
This sample data shows some sample numbers:
WITH limitdata AS
     (SELECT 1066230 req_header_id, 60002872 req_num, 2042944 line_location_id, 1095545 po_header_id FROM DUAL UNION ALL
      SELECT 1082412, 60004988, 2086260, 1095545 FROM DUAL)
SELECT *
  FROM limitdata;I tried to do it via:
SELECT DISTINCT prla.requisition_header_id
              , prla.creation_date
              , prha.segment1
              , plla.line_location_id
           FROM po.po_requisition_lines_all prla
              , po.po_requisition_headers_all prha
              , ap.ap_suppliers pv
              , ap.ap_supplier_sites_all pvsa
              , po.po_line_locations_all plla
              , po.po_lines_all pla
          WHERE prla.vendor_id = pv.vendor_id
            AND prha.requisition_header_id = prla.requisition_header_id
            AND prla.vendor_site_id = pvsa.vendor_site_id(+)
            AND prla.line_location_id = plla.line_location_id
            AND plla.po_line_id = pla.po_line_id
            AND prha.requisition_header_id = (SELECT MAX(requisition_header_id)
                                                FROM po.po_requisition_lines_all prla2
                                               WHERE prla2.line_location_id = plla.line_location_id)
            AND pla.po_header_id = 1095545;But that still return s the same 2 lines as in the sample data.
Apologies for revealing my ineptitude and stupidity by asking this question, but I wondered if anyone might be able to advise please about where I am going wrong?
Any advice much appreciated.
Thanks

Answer 1

You might try the E-business suite - EBS General discussion group for users more familiar with this module.
Meanwhile -
What I do when I'm trying to find which record in an ebs query is causing me to return more than (or less than) the desired rows is to start the query with one table and appropriate "where" clause, then add 1 table at a time until I get the duplicate rows. Then I can investigate why that data is that way. Frequently it comes down to an "active" flag or an end date or other criteria that differentiates the rows. In just a short look at your code, I would check out the vendor sites table, as there are frequently more rows than you anticipate in sites tables.
And - I know there are frequently a boat load of tables that look "not needed" but really are - but are you sure you need all those tables to accomplish your goal? Can you eliminate some of the supplier tables, that could be giving you unexpected data.
Good luck!